Apparatus for making hollow reinforced concrete bodies



Aug. 9, 1960 K. D. sYLvr-:sTER

APPARATUS FOR MAKING HOLLOW REINFORCED CONCRETE BODIES 4 Sheets-Sheet 1Filed March 14, 1955 INVENToR. Hennef/7 D 55//1/e5er BY g/v/ ir/fam...

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N Q Q Aug. 9, 1960 K. D. sYLvEsTER APPARATUS FOR MAKING HOLLOWREINFORCED CONCRETE BODIES 4 Sheets-Sheet 2 INVENTOR.

Filed March 14, 1955 Hennef/7 Q .Sg/Veser Arrow/Ey:

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Aug. 9, 1960 K. D. sYLvEsTER APPARATUS FOR MAKING HOLLOW REINFORCEDCONCRETE BODIES Filed March 14, 1955 4 Sheets-Sheet 3 Q new INVENTOR./Venneh y/a/es/er llmIm-.H-IIMH m I m H. rH.-.| ./V/A ...n f. n.

Aug. 9, 1960 K. D. sYLvEsTER APPARATUS FOR MAKING HOLLOW REINF'ORCEDCONCRETE BODIES 4 Sheets-Sheet 4 Filed March 14, 1955 INVENTOR.

K/e/me//z Q y/Vesfe/-- BY Z040 Llinited States l Patented Aug. 9, 1950APPARATUS FOR MAKING HOLLOW REIN- FORCED CONCRETE BODIES FiledMar. 14,1955, Ser. No. 494,036

Claims. (Cl. 25-30) This apparatus relates generally to apparatus andmethods for casting elongated hollow concrete bodies. More particularlyit pertains to apparatus and methods adapted for the manufacture ofhollow bodies utilizing pre-stressing.

It is well understood that theV pre-stressing of concrete structure orbodies has certain advantages. It tends to prevent the development ofcracks, and with bodies of considerable length it may serve to providesuicient strength for handling without breakage. As applied to theconstruction of concrete piles, thebodies have been cast with Aopeningsextending longitudinally the same through which reinforcing members arestrung, after which the reinforcing members are tensioned and thenbonded to the body by lling the openings with cement grouting. Onedifculty with this procedure is that it is not well adapted tomanufacture of piles of considerable length. Furthermore thediiliculties involved in steinging reinforcement through the openings,and-filling lche openings with grouting, increases with increase in thelength of the pile. Making the pi'le in sections, and then attaching thesections together, is unsatisfactory in several respects, particularlybecause it is diicult to secure a joint having adequate strength, andbecause of the handling expense involved.

In place of the procedure described above, it is possible to pretensioncables or steel wires and cast the concrete body about the same, wherebyafter the concrete has hardened, release of the cables applies thedesired stressing to the concrete. This method has likewise been diicultif not impossible to apply to the making of relatively long concretebodies, particularly where it is necessary to have ,a hollowconstruction.

In general it is an object of the present invention to provide apparatusfor the manufacture of pre-stressed concrete bodies, and which inparticular is applicable to hollow bodies of extended lengths.

Another object of the invention is to provide apparatus of the abovecharacter which makes possible the pretensioning of reinforced members,with direct bonding of the concrete to the reinforcement.

Another object of the invention is to provide lan app-aratus which doesnot have the limitations of previous casting procedures and which can beused for the rapid and economical manufacture of hollow bodies tovirtually any length desired.

Additional objects and features of the invention will appear from thefollowing description of which the preferred embodiment has been setforth in detail in oonjunction with the accompanying drawing.

Referring to the drawing:

Figure l is a side elevation view, partly in section,

illustrating apparatus in accordance with the present inf vention.

Figure 2 is a cross section view taken along the line 2-2 of Figure l.

Figure 3 is a cross section view taken along the line 3-3 of Figure 1.

'Figure 4 is a detail in side elevation and in section, illustrating themanner in which the core of Figure 1 is shifted for successive castingoperation.

Figure 5 is a detail in section illustrating another embodiment of `theinvention.

`Figure 6 is a side `elevational view in section illustrating anotherembodiment of the invention in which the core is collapsible.

'Figure 7 is -a cross-sectional detail taken along the line 7 7 ofFigure 6.

. Figure 8 is a side elevational detail in section illustrating anotherembodiment of the invention in which fluid is introduced i-nto the spacewithin the poured concrete.

Figure 9 is a side elevational detail in section similar to Figure 8 butshowing another embodiment in which sand or like divided material isintroduced into the space within the poured concrete.

Figure l0 .is a side elevational View similar to Figure l, butillustrating another embodiment of the invention.

Figure 1l is a cross-sectional detail taken along the lines 11-11 ofFigure l0.

Figure l2 is a cross-sectional detail taken along the line l2-12 ofFigure l0.v

The apparatus illustrated in Figure l consists of an elongated rigid bed10, which can conveniently be made of reinforced concrete, and whichrests upon the ground. The end portions 11 of the bed may be uprightextern sions as illustrated. The upper surface 12 of the bed may belined with sheet metal or as otherwise formed to provide `a suitablecasting surface. In this instance it is assumed that the body to be castis a cylinder, and there fore the surface 12 is semi-cylindrical. Asupplemental form 13, which may be in two or more sections, is removablypositioned upon the bed, and forms with the bed fa complete mold forcasting the exterior of the body. At suitable intervals along the lengthof the bed, the forms y13 are provided with the removable doors 14, whenremoved permit the introduction of a concrete mix.

The upright extensions 1-1 at the ends of the bed provide means forcarrying the anchoring members 16. These members may be steel plates ofsuitable strength` removably attached to the end extensions 111 as bymeans of bolts 17. The anchoring members have suitably disposed openingsfor receiving the metal reinforcing members 18. These members may, forexample, be steel wire or cable of the type used in the making ofprestressed concrete structures. Heads 19 are applied to the extremitiesof members 18 and each member is tensioned to a pre-determined degree bysuitable hydraulic jacks or other means well known to those familiarIwith pre-tensioning operations. After a member has been tensioned tothe degree desired, the heads 19 are applied in such a manner as toretain the tension. Assuming the casting of a hollow cylinder, it isdesirable that the members 18 be spaced circumferentially labout thecentral horizontal axis of the complete form. An end wall 21 is provided`at that end of the bed where the pouring of the concrete mix is tocommence. In Figure l it is assumed that pouring is to commence at theleft hand end. The end wall 21 is apertured to receive the members 18,and may be positioned while the members 13 are being attached to theplate 16.

Within the complete casting form there is a core 22 which in thisinstance is in the form of a pipe or conduit, having ya .slight taper asillustrated. Initially one end of this form abutts against the wall 21.The other end is carried by `the guide means 23, which in this instanceis in the form of a ring apertured toV accommodate the 3 reinforcingmembers 13. The core is attached to a pullrod or c-able 24, whichextends through the opening in one of the lbed extensions 11, and whichmay connect with suitable means for shifting the core after each pouringoperation.

It will be noted from Figure 1. that the length of the core 22 isslightly greater than the distance between the doors 14. The overalllength of the casting form may be many times the length of the core.

Use of the apparatus described above and the carrying out of my methodis as follows:

The core 22 is first positioned at one end of the complete form, as forexample, the left hand end as shown in Figure 1. In order to hold theleft hand end of the core centrally' with respect to the outer form, itmay be necessary to insert a temporary prop between the smaller end ofthe core and the bed. The first door 14 overlying the core is removedand la suitable concrete mix introduced. Vibration or like techniquescan be applied for proper fiow of the mix. When the space about .thecore has been completely filled, the apparatus is permitted to standuntil the cement has hardened a suicient amount to be self supporting.When the concrete has hardened sufiiciently, the core is shifted bypulling upon the cable 24, until its small end projects into thepreviously poured concrete a short distance as shown in Figure 4'. Thesecond door 14 is now removed and a second pour of concrete applied.Before making the second pour it is desirable to wash or jet off theexposed end face 26 of the previous pour, in order to insure a goodbond. After the second pour, the apparatus is permitted to stand untilthe concrete is self-supporting, after which the core 22 is againshifted for la third pour. It -is evident that this procedure can berepeated until the entire length of the body has been poured. After thelast pour the apparatus is permitted to stand until the concrete hasattained suflicient hardness for an effective bond with the reinforcingmembers 1S. The forms 13 are now removed, the projecting ends of thereinforcing members 18 severed, and the cast body removed from the -bedas by rolling it sideways. After the body has been removed, the core 22can be removed from the end of the body.

it will be evident that the apparatus and method described abovepossesses many advantages over prior methods for the manufacture ofhollow concrete piles or other bodies of extended length. The method isrelatively economical, particularly because the apparatus is not undulycomplicated and expensive, `and because the labor involved is notexcessive. Although the body is cast with successive pours, perfectbonds are provided between successive pours, thus avoiding difficultiespreviously experienced in joining sections of pre-stressed concretepiles. Furthermore the pre-stressing squeezes the junctions betweenpours, and in general makes the complete cast body into a homogeneousunit. The method has no limitations with respect to the length of thebody which can be cast. Thus it is possible to make hollow bodies inlength heretofore impossible with prevailing methods.

Immediately prior to each pour, it is possible to introduce additionalstandard reinforcement into the space about the core. However, generallyit is unnecessary to use standard reinforcement as distinguished fromprior methods Where it is customary to use screening or likereinforcement to supplement the tensioning members.

Although the method and apparatus has been described above as applicableto the manufacture of a cylindrical body, it will be evident that othershapes can be made as desired, as for example, polygonal, rectangular orsquare.

With the method as described with reference to Figure l, each castingoperation completely fills the space about the core, to contract thespacing ring 23. If desired each pourcanstop short of completely fillingthe space about the Vfcore; as indicated for example in Figure'S. Inthis inst-'ance'insteadflof usingthe'spacing-ring 23 of Figure l,

the ring 27 is provided which has its periphery contacting thereinforcing members 18. The length of the core 22 can be made somewhatgreater than in Figure l. As indicated in Figure 5, the previous pourhas stopped short of completely filling the space about the core, thusleaving relatively uneven end face 28. in the final casting operation,the space is, of course, completely filled with the mix.

The .apparatusv is not limited to the use of a tapered core. Any corestructure which can be shifted from one position to the next can beused. In Figures 6' and 7 I have shown a core of the collapsible type.In'this instance the core consists of a longitudinally split cylinder29, which is connected by the links 30` with the central rod 31. As iswell known by those familiar with the collapsible forms of this type,rod 31 can be shifted longitudinally to spring the cylinder 29, wherebyedges 29a and 291; are brought into overlapping engagement, to reducethe effective diameter. After each casting operation, a suitable toolcan be used for collapsing the'form, shifting it to its new position,and then extendingthe form for the next casting operation.

As shown in Figure 8 the core form 35 is cylindrical Aand isco-nstructedlike a piston. Pipe 36 connects with a source of fluid under pressure,which may be air or other gas or preferably water or other suitableliquid. By controlled yintroduction of uid under pressure the core 35can `be intermittently or continuously moved as the pour proceeds.Maintenance of iiuid pressure serves to hold the poured mix in placethus facilitating movementof the form before the preceding pour hashardened to the point of being self-supporting.

Figure 9 shows another embodiment in which sand or other divided solidmaterial is introduced for the purpose of holding the poured walls ofconcrete in place. In this instance the core 38 can be cylindrical orsubstantially cylindrical, and the wall 39, corresponding to the wall 21of Figure 4, is imperforate. The core 38 is attached to a bar or cable41 by means of which the core can be moved longitudinally. A nozzle 42connects with the hose 43 and serves to introduce sand or like materialinto the space 44. The wall 46 of the form 38, through which the nozzle42 extends, is shown provided with screened openings 47 for escape ofair. When utilizing the embodiment of Figure 9, the sand is conveyedpneu-l matically `through the hose 43 to fill the space 44. The

filling of space 44 can be intermittent following intermittentlongitudinal movements of core 38 or if the core is moved continuously,then the filling can proceed continuous-ly and progressively. FillingVof this space with `sand or like material forms a medium for theabsorption' annular guide means S3 is mounted upon the Vcore 51 and isadapted to engage the tensioned reinforced members 18. An annular member54 is attached to the Aextremity of extension 52 and is provided withopenings for slidably accommodating theV reinforcing members '18.V Apipe or cylindrical member S6 has its one `end secured` to annularmember 54 and its other end serves to carry anjannular member 57, whichis disposedl in the same lplane as guide means 53.

Spirally wound reinforcement 58 is shown positioned within the pipe 56,with the convolutions relatively close together. For that part of thepile that has been poured and which is illustrated in Figure l, thereinforcement 58 has its convoiutions spread apart and extending aboutthe tensioned reinforcing members 18. Suitable means, such as the pullcable 59, permits the core 51 to be moved between successive pouringoperations.

The upper part 61 of the exterior form shown in Figures -12 has anextended slot 62 to facilitate pouring operations.

Operation of the apparatus shown in Figures 10-12 is as follows:Preparatory to casting a pile, suicient spirally wound reinforcement ispacked into the pipe 56 to suffice for the complete pile. After members18 have been positoned and tensioned, a part of the spirally foundreinforcement is distributed along the core 51 preparatory to a pouringoperation. Thereafter the rst pour is carried out, and after theconcrete has partially hardened, the core together with the extension51, is moved for the next pouring operation. Here again, before the pouris commenced, a suicient amount of spirally wound reinforcement iswithdrawn from the pipe 56 and is distributed along the tensionedreinforcement 18, in the same manner as explained above.

Although the apparatus shown in Figures l0l2 is particularly adapted forthe placement of the spirally wound reinforcement, it will be evidentthat such reinforcement can likewise be used with the apparatus ofFigure 5. Thus, before positioning the reinforcing members 18, thesprally wound reinforcement can be introduced into the form.Reinforcement 18 is threaded through the spiral reinforcement andtensioned in the matter previously described. Then the spiralreinforcement is properly distributed and attached to reinforcingmembers 18 by suitable means such as wire ties or tack welding.

I claim:

`1. In apparatus for forming hollow concrete bodies of extended lengthhaving longitudinal pre-stressed reinforcement therein, a rigidhorizontal casting bed, means for anchoring tensioned reinforcingmembers to the ends of the bed with said members being spacedcircumferentially about the horizontal axis of the bed, the uppersuryface of the bed providing a lower portion of a casting form,additional casting form means being positioned upon the bed to formtherewith a complete form for casting the exterior of the body, saidlform means having openings therein at longitudinally spaced intervalsfor the introduction of a concrete mix, and Ia core aligned with theaxis of the bed and disposed within the reinforcement, said core havinga length substantially less than the length of the bed and a slightlytapered configuration so as to be readily movable lengthwise thereof todifferent positions for successive casting operations to form onefinished body, said core being further provided with annular guide meansadjacent its point of greatest diameter and kadapted to slidingmovements relative to said reinforcement and exterior form.

2. In apparatus for forming hollow concrete bodies of extended lengthhaving a longitudinal pre-stressed reinforcement therein, a horizontalrigid structural bed, means for anchoring tensioned reinforcing membersto the ends of the bed, with said members being disposed as desired inthe finished product, the upper surface of the bed forming a lowerportion of a casting form, additional casting form means removablypositioned on the bed to form with the bed a complete form for shapingthe exterior of the concrete body, said form means having openingstherein for introducing a concrete mix, and rigid means forming a corewithin the form, said core being formed so as to be readily movablelongitudinally of the bed positions for successive casting operations to:form one complete integral body bonded to the tensioned members, saidcore being further provided with annular guide means adjacent its pointof greatest diameter and adapted to slid* ing movements relative to saidreinforcement and e terior form.

3. Apparatus as in claim l together with means for introducing uid underpressure into the space formed by said core.

4. Apparatus as in claim 3 in which said means for introducing uid underpressure serves to move the core longitudinally from one position to thenext.

5. In apparatus for forming hollow concrete bodies of extended lengthhaving longitudinal pre-stressed reinforcement therein, a rigidhorizontal casting bed, means for anchoring tensioned reinforcingmembers to the ends of the bed with said members being spacedcircumferentially about the horizontal axis of the bed, the uppersurface of the bed providing a lower portion of a casting form,additional casting form means being positioned upon the bed to formtherewith a complete form for casting the exterior of the body, saidform means having openings therein at longitudinally spaced intervalsfor the introduction of a concrete mix, a core alined with the axis ofthe bed and disposed within the reinforcement so as to provide a spaceWithin a cast body, said core having a length substantially less thanthe length of the bed and a slightly tapered configuration so as to bereadily movable to different positions for successive casting operationsto form one finished body, said core being further provided with annularguide means adjacent its point of greatest diameter and adapted tosliding movements relative to said reinforcement and exterior form, andmeans associated with said core for introducing divided solid materialinto said space.

References Cited in the le of this patent UNITED STATES PATENTS 517,808Ransorne Apr. 3, 1894 1,123,832 Atterbury Ian. 5, 1915 1,309,978 CarrJuly l5, 1919 1,486,204 Trullinger `et al. Mar. l1, 1924 1,722,038Dougherty July 23, 1929 1,920,716 Schafer Aug. 1, 1933 2,153,741 CobiApr, 11, 1939 2,172,703 Freyssinet Sept. l2, 1939 2,306,037 Colvin Dec.22, 1942 2,394,227 Barber Feb. 5, 1946 2,511,761 Barber et al June 13,1950 2,609,586 YParry Sept. 9, 1952 FOREIGN PATENTS 10,620 AustraliaN'ov. 29, 1927 691,323 Great Britain May 13, 1953

